Polymerization of acrylonitrile in the presence of preformed homopolymers



United States Patent G POLYMERIZATION F ACRYLONITRILE IN THE PRESENCE GFPREFGRMED HOMOPOLYMERS' Harry W. Coover, In, and Joseph B. Dickey,Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, N. Y., acorporation oiNew Jersey No Drawing. Application October 21, 1952,Serial No. 316,055

3 Claims. (Cl. 260-455) This invention relates-to the polymerization ofacrylonitrile in the presence of preformed polymers, and to articlesobtained therefrom.

In our copending application Serial No. 164,854, filed -May 27, 1950(now U. S. Patent 2,649,434, dated August 18, 1953), We have shownthat'valuable polymer products can be obtained by polymerizingacrylonitrile in the presence of: homopolymers of acrylamides,itaconamides, citraconamides, esters of acrylic and methacrylic acidsand vinyl carboxylic esters.

It has been previously proposed to polymerize acrylonitriie in thepresence of polyvinyl resins, such as polyvinyl acetate (U. S. Patent2,123,599, dated July 12, 1938). The polymers obtained according to thesuggested method in U. S. Patent 2,123,599 can be used to preparesynthetic fibers, which are susceptible to many of the known organicdyes. A serious drawback with this method is that the fibers thusobtained have too low a softening temperatureto be of. commercial value,softeningbeingobserved at temperatures as lowas. 145 C.

Attempts have been made to increase the dycability of polyacrylonitrilefibers by interpollymerizing acrylonitrile with certain. monomers whosepolymers have anafiini'ty for'dyes. While this procedure doesgive.polymer products, from whichfibers having good dyeing properties can beobtained, a serious drawback, such as that. mentioned above, arises incertain instances, a substantial lowering of. the softening point. ofthe: fiber being observed. For example-while an interpolym'er.ofiacrylonitrile and vinyl acetate'containingabout 80 percent'by weightofacrylonitril'e: can-be drawn. into fibers susceptible to. dyeing,'thesoftening point of. such fibers is too low for practical purposes;softeningof the fibers being'observcd ata'bout 150 -170 C.

Other attempts have been made: to: increase the:'dyeability of"polyacrylonitrile fibers by mixing witlr'the polyacrylonitrile, beforespinning, other polymeric materials which are dye-susceptible: Thisprocedure likewise provides fibers having good dyeing properties,however, many of these fibers show a low softening point, and inadditionmany show segmentation into" their individual components along theirhoriz'ontal axis; For example, it can be demonstrated that mixturesofpolyvinyl acetate and polyacr-ylonitrile, when dissolved infeit'he'rN;N-dinrethylformamide or N,N'-dimethylacetamide in proportions varying;from to 50 percentweight of polyvinyl acetate based on the 'tbtal weightof the mixe'd polyacrylonitrile-and polyvinyl acetate, form' grainydopes which separate into two liquid layerson standing. This isalso'true of many other polymeric compounds; natural or synthetic, whichare soluble in the'a'bove solvents; Fibers which form from thesenon-homogeneous solutions ormixtures-of polya'cryl'onitrile andpolyvinyl acetate are too lowin softening temperaturetobe of practicalvalue; and also are subject to the defect of segmentation. is' a m nbeca s ffls 9. i semis 9 4a ass of the spinning solution and the factthati't' is" gerr- 2,787,606 Patented Apr. 2, 1957 "ice erallyknown-that polyacrylonitrile'is not compatible with many organicsubstances.

We have now made the unusual and valuabledi'scovcr'y that stablesolutions of acrylonitrile polymers which do not separate into distinctlayers on standing, and from which fibers of homogeneous character canbe spun, can be prepared by polymerizing acrylonitrile in the presenceof preformed polymers which have not been separated from theirpolymerization medium prior to the addition of monomeric acrylonitrile.These fibers are characterized by a softening point higher than theinterpolymers referred to above, and do not exhibit the segmentationdefect shown by many or" the fibers prepared from certain prior artmaterials comprising. polyacrylcnitrile.

It is, therefore, an object of our invention to provide acrylonitrilepolymer compositions. A further object of our invention is to providemethods for making these modified polymer compositions. Still anotherobject is to provide homogeneous. solutions obtained from these polymercompositions comprising acrylonitrile. Another object is to providefibers from these homogeneous solutions, and methods for making thesefibers. Other objects will. become apparent from a consideration of thefollowing description and examples.

According to our invention, we provide polymer compositions comprisingacrylonitriie by polymerizing acryionitrile in the presence of apreformed polymer which has not been separated from its polymerizationmedium prior to the addition: of the acrylonitrile. When the-pre formedpolymer is separated from its polymerization medium, and rcdissoived'inasolvent, or suspended inan 'incertain instances, such as with polyvinylacetate. When the acrylonitrile is added to the preformed polymer beforeseparation ofthe polymer from the reaction medium, a certain number ofgroups in the polymer chain apparently remain reactive, and theacrylonitrile is able to increase the length of the polymer chain. Thecompositions obtained according to our invention are not to be confusedwith simple interpolymers which have a low softening point as has beennoted above.

The polymer compositions of our invention contain from 5 to 95 percentby weight of acrylonitrile and from 95 to 5- percent by weight of theother monomer from which the preformed hoinopolyrner is-obtainedQ Thoseof our compositions containing from about 691695 percent by weight of'acrylonit'rile have been found to be especially useful as fiber foriningmaterials; However, all of'our compositions'in the 5 to 95 percent rangeo'f'acrylonit'rile are compatible with each other, withpolyacrylonitrile, or with other acrylonitrile polymers containing atleast percent bywight of' acrylonitrile, in-all proportions, but themost usefulmiXtu res-are' from 5 to pans-"15y weight of one or more ofthe polymers of the invention with from 95 to 5 parts by Weight ofpolyacryionitrile. Monomers, whose polymers were not heretoforecompatible with polyacryionitrile can thus be polymerized according toour invention to give polymers which are highly compatible withpolyacryionitrile.

Thepret'orined polymers which are. useful in practicing ourinvention canbe prepared by polymerizing et'irenoid unsaturatio'n" according. tomethods well known to the art. As etheno'id compounds, we have foundthatmaleamide tuinaraniides, male'ama'tes, furnaramates, itacona mates andcitra'conaniates are especially. suitable for pro} viding thecompc'sitionsfof the" invention. When from to 95""parts by "weight" ofacrylonitrile" is added to from 95 to 5 parts by weight of thehomopolymcr of one'of the above ethenoid compounds and the mixtureheated in the presence of a polymerization catalyst until theacrylonitrile is substantially polymerized, particularly usefulcompositions are obtained.

'The maleamides which can advantageously be used in our invention areselected from those represented by the following general formula:

wherein R and R1 are as above defined. Typical fumaramides includefumaramide, N-methyl fumaramide, N- ethyl fumaramide, N-propylfumaramide, N-isopropyl fumaramide, N-n-butyl fumaramide, N,N-dimethylfumaramide, N,N'-diethyl fumaramide, N,N-di-n-butyl fumaramide,N-methyl-N-ethyl fumaramide, N-methyl- N-bntyl fumaramide,N,N-tetramethyl fumaramide, N, N-tetraethyl fumaramide, N,N di-methylN,N'-diethy1 fumaramide, etc.

As maleamates, we can advantageously use those represented by thefollowing general formula:

wherein R and R1 are as above defined and R2 represents an alkyl groupcontaining from 1 to 4 carbon atoms. Typical maleamates include methylmaleamate, ethyl maleamate, propyl maleamate, n-butyl maleamate, N-methyl methyl maleamate, N-ethyl methyl maleamate, the N-methyl butylmaleamates, N-dimethyl methyl maleamate, N-dimethyl ethyl maleamate,N-dimethyl nbutyl maleamate, the N-dibutyl methyl maleamates, etc. Asfumaramates, we can advantageously use those represented by thefollowing general formula:

CH-E-O R:

Ri-N-O-OH wherein R, R1 and R2 are as above defined. Typical fumaramatesinclude methyl fumaramate, ethyl fumaramate, propyl fumaramate, n-butylfumaramate, N- methyl methyl fumaramate, N-methyl ethylfumaramate, theN-methyl butyl fumaramates, N-dimethyl methyl furnaramate, N-dimethylethyl fumaramate, N-dimethyl etc,

n-butyl fumaramate, the N-dibutyl methyl fumaramates,

4 As itaconamates, we can advantageously use those represented by thefollowing general formulas:

wherein R, R1 and R2 are as above defined. Typical itaconamates includemethyl itaconamate, ethyl itaconamate, propyl itaconamate, the butylitaconarnates, N- methyi methyl 'itaconamate, Nmethyl ethyl itaconamate,N-methyl propyl itaconamate, N-methyl n-butyl itaconamate, N-dimethylmethyl itaconamate, N-dimethyl ethyl itaconamate, N-dimethyl n-butylitaconamate, the N-dibutyl methyl it-aconamates, etc.

As citraconamates, we can advantageously use those represented by thefollowing general formulas:

wherein R, R1 and R2 are as above defined. Typical citraconamatesinclude methyl citraconamate, ethyl citraconamate, propyl citraconamate,the butyl citraconamates, N-methyl methyl citraconamate, N-methyl ethylcitraconamate, N-methyl propyl citraconamate, N-

methyl n-butyl citraconamate, N-dimethyl methyl citraconamate,N-dimethyl ethyl citraconamate, N-dimethyl n-butyl citraconamate, theN-dibutyl methyl citraconamates, etc.

In preparing the polymer compositions of our invention, a monomerselected from those represented by the above general formulas ispolymerized until homopolymerization is substantially complete, i. e.further heating produces no additional polymerization and theacrylonitrile monomer is then added and the polymerization continueduntil the acrylonitrile is substantially polymerized, i. e. from aboutto percent.

The polymerization can be accelerated by the use of a well-knownpolymerization catalyst. Such catalysts are commonly used in the art ofpolymerization, and our invention is not to be limited to any particularcatalyst materiaL' Catalysts which have been found to be especiallyuseful comprise the peroxide polymerization catalysts, such as theorganic peroxides (e. g. benzoyl peroxide, acetyl peroxide, acetylbenzoyl peroxide, lauryl peroxide, oleoyl peroxide, triacetone peroxide,urea peroxide, t-butyl hydroperoxide, alkyl percarbonates, etc.),hydrogen peroxide, perborates (e. g. alkali metal perborates, suchasthose of sodium and potassium, etc.), persulfates (e. g. alkali metalammonium persulfate, etc. Other catalysts such as the ketazines, azines,etc. can be used. The quantity of catalyst used can be varied, dependingon the monomer, amount of diluent, etc. Sufficient catalyst can be usedto homopolymerize the ethenoid monomer selected from those representedby the above general formulas and the monomeric acrylonitrile, or anamount of catalyst sufficient to polymerize only the ethenoid monomercan be used, and additional catalyst can be added with the acrylonitrilemonomer to complete the polymerization. The catalyst, a'ddeclalong withacrylonitrile may be the same catalystthat'was used to polymerize theother ethenoid monomer. We. have found that it is especiallyadvantageous to use an amount of catalyst sufficient to polymerize onlythe. first monomer, and then upon addition of the acrylonitrile to add afurther amount of catalyst at that time. This procedure provides areadier means for regulating the molecular weight distribution of thepolymer composition.

The temperatures at which the process of our invention can be carriedout vary from ordinary room temperature to the reflux temperature of thereaction mixture. Generally, a temperature of from 25 to 75 C. issufficient.

If desired, emulsifying agents can be added to the reaction mixture todistribute uniformly the reactants throughout thereaction medium.Typical emulsifying agents include the alkali metal salts of certainalkyl acid sulfates (e. g. sodium lauryl sulfate), alkali metal salts ofaromatic. sulfonic acids (sodium isobutylnaphthalenesulfonate), alkalimetal or amine addition salts of sulfosuccinic. acid esters, alkalimetal salts of fatty acids containing from 12 to 20 carbonatoms,sulfonated fatty acid amides, alkali metal salts of alkane sulfonicacids, sulfonated ethers (e. g. aryloxy polyalkylene ether sulfonates),etc.

The polymerization can be carried out in the presence of chainregulators, such ashexyl, octyl, lauryl, dodecyl, myristyl mercaptans,etc., whichimpart improved solubility propertiesto thepolymer'compositions. If desired, reducing agents such asalkali metalbisulfites (e. g. potassium, sodium, etc; bisulfites) can be added toreduce the time required for the polymerization to be effected.

The following examples will serveto illustrate further the mannerwhereby we practice our invention.

Example 1 9.7 g. of N,N -dimethylfumaramide were suspended in 100 cc. ofdistilled water along with. 0.1 g. of ammonium persulfate, 0.1 g. ofsodium bisulfite, and 1 g. of a sulfonated ether type ofemulsifyingagent. The resulting emulsion was allowed to polymerize for 16 hours at50 C. and then cooled downto room temperature. A solution of 0.5 g. ofacrylonitrile, 0.01 g. of ammonium persulfate, and 0.01 g. of sodiumbisulfite in cc.-of water was. added and the polymerization completedby,- tumbling at 50 C. for. 8 hours; The emulsion was broken by theaddition of a concentrated salt solution, and the precipitated polymerwas filtered, washed, and dried. On analysis, the polymer compositionwas found to contain 95 percent byweight, of N,N-dimethylfumaramide.

Fibers obtained from a mechanical mixture containing 30 percent byweight of the polymer obtained and 70 percent by weight ofpolyacrylonitrile, by extrudinga solution of the mixture inN,N-dimethylformamide into a precipitating bath, had'a tenacity of 3.4g. per denier, an extensibility of percent, a sticking temperature of210C, and shrank. 9 percent in boiling water.

Example 2 2 g. of.N,N,N',N-tetramethylfumaramide. was emulsifiedin 80cc. ofwater containing 2 g. ofpotassiurnlaurate, 0.02 g. of potassiumpersulfate and 0.02 g. of sodium bisulfite; The emulsion wasv allowedto-polymerize for 16 hoursat C. There were then added 8. g. of

. aerylonitrile, 0.1 g. of potassium persulfate and 0.1 g.

and- 0.1 g. of sodium bisulfite;

6 V which do not separate; into distinct layers on standing and fromwhich fibers and films of homogeneous: character can be spun, extruded"or cast. Examples 2 g. of N,N-di-isopropylfumaramide were suspended in1.8 cc: ofwat'er along with 002' g, of ammonium persulfate, 0.02'g. ofsodium bisulfite and 1.1 g. of a sulfonated ether type of emulsifyingagent. The resulting emulsion was allowed to polymerize for 1.6 hours at50 C., then cooled to room temperature, and a dispersion containing 8 g.of acrylonitrile, 0.1 g. of ammonium per-sulfate, 0.1 g. potassiumbisulfite and 2 g. of a. sulfonated ether (Triton 7 20 in 50cc. of waterwereadded. After tumbling the resulting emulsion at 50 C. for 2 hours,the polymer productwasprecipitatedby the addi tion of a sodium chloridesolution to give 9.8 g. of product containing 20 percent by weight ofN,N'-di-isopropylfumaramide.

Fibers obtained from a solution of. a mechanical mix ture of 5 partspolyacrylonitrile and parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.1 g. per denier,an extensibility of 20 percent, a sticking, temperature of 215 C., andshrank only 7 percent in boiling water.

Example 4 2 g. of N,N'-diethylmaleamide were emulsifiedincc. of watercontaining 1.1 g. of asulfonated. ether type of emulsifying agent and0.04 g. of potassium persulfate. The emulsion washeated at50 C. for 16hours, and the emulsion cooled to-room temperature. There were-thenadded 8g. of acrylonitrile, 0.1 g. of potassiumrpersulfate v Thereaction mixture was then allowed to stand at 2-5 C. for. 16 hours. Theprecipitated polymer. weighed 8,7 g. and contained 20 percent by weight,of N,N'-diethylmalearnid e.

Fibers were then spun byextruding a solution of the polymer inN,N-dimethylformamide into aprecipitating bath. The fibers thus obtainedhad a tenacity of- 3.3- g. per denier, an extensibility of 20 percent, asticking temperature of 215 C., and shrank onlyv 8 percentin boilingwater. The fibersremained soft after being subjected to the usualdye-baths.

Contrasted with the fibers: obtained above, fibers ob tained from aninterpolymer'containing. 20 percent by weight of N,N'-diethylmaleamideand 80 percent aer-ylonitrile hada tenacityof- 2.3 g; per denier, anextensibility of 11 percent, a sticking temperature of (3., and shrank27 percentin boiling water.

Example. 5

2g. of N,N-dirnethylmaleamidei were suspended in 18 cc. of Wateralongwith' 0.02 g. of ammonium persulfate, 0.02 g. of. sodium bisulfiteand 1.1 g. of a sulfona'ted ether type of emulsifying agent. Theresulting'emul'sio'n was allowed to polymerize-for l2-hours at 35 C.,then cooled down to room; temperature and added to a dispersioncontaining 8 g. of acrylonitrile, ,5 g. of ammonium persulfate,,% g; ofsodium bisulfite' and" 2 g'. of a sulfonated ether type of emulsifyingagent in 50 cc; of water. After tumbling the reaction mixture at 50 C.for 2 hours, the polymer product was precipitated by the addition of anaqueous solution of sodium chloride to give 9.7 g; of polymer productcontaining 20 percent by weight of'N,N*-dimethylmaleamide.

Fibers were then span from the product obtained above by extruding asolution of the polymer in N,N-dimethylformarnide into a precipitatingbath. The fioers thus obtained had a tenacity of 3.5 g. per denier, anextensibility of -2 1 percent, a sticking'temperature of 220 (3., andshrank 8 percent in boiling water.

Fibers obtained from a solution of a rneehanical mixture of' 10 partspolyacrylonitrile and 90' partsqfith above polymer" and extrudingth'esolution into" a preeipi was allowed to stand at 25 C. for 12 hours.

C., and shrank 6 percent in boiling water..

Example 6 cooled to room temperature, and a mixture containing 8 g.acrylonitn'le, 0.1 g. of ammonium persulfate and 0.1 g. sodium bisulfitewere added. The reaction mixture The precipitated polymer weighed 9.4 g.and contained 19 percent by weight of N-methylmethylfumaramate.

Fibers obtained from this polymer had a tenacity of 3.2 g. per denier,an extensibility of 19 percent, a sticking temperature of 225 C. andshrank 8 percent in boiling water.

Fibers obtained from a solution of a mechanical mixture of 20 partspolyacrylonitrile and 80 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.4 g. per denier,an extensibility of 18 percent, a sticking temperature of 225 C., andshrank 6 percent in boiling water.

Example 7 4 g. of N,N-dimethylethylfumaramate were suspended in 40 cc.of water containing 0.04 g. of ammonium persulfate, 0.04 g. of sodiumbisulfite and 2.2 g. of a sulfonated ether type of emulsifying agent.The resulting emulsion was allowed to polymerize for 16 hours at 50 C.,then cooled to room temperature and a dispersion containing 6 g. ofacrylonitrile, 0.1 g. potassium persulfate, 0.1 g. sodium bisulfite, and2 g. of a sulfonated ether (Triton 720) in 50 cc. of water was added.There was thus obtained 9.4 g. of polymer product containing 43 percentby weight of N,N-dimethylethylfumaramate.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Example 8 and contained percent by weight of N-isopropylmethylmaleamide.It was soluble in N,N-dimethylformamide or N,N-dimethylacetamide. Fibersobtained from these solutions had a sticking temperature of 230 C.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Example 9 8 g. of N-methylmethylitaconamate were suspended in 80 cc. ofwater containing 0.1 g. of ammonium persulfate, 0.1 g. of sodiumbisulfite, and 5 g. of a sulfonated other type of emulsifying agent. Theemulsion was allowed to polymerize for 16 hours at 50 C., at the end ofwhich time polymerization seemed to be complete. The reaction mixturewas then cooled and added to a dispersion containing 2 g. ofacrylonitrile, 0.05 g. of ammonium persulfate, 0.05 g. of sodiumbisulfite, and 1 g. of a sulfonated ether (Triton 720) in 30 cc. ofwater. After tumbling the reaction mixture for 4 hours at 50 (3., there8 were obtained 9.7 g. of polymer containing 83 percent by weight ofN-methylmethylitaconarnate.

. The polymers can be mixed with polyacrylonitrile in all proportionsand dissolved to give-stable solutions which do not separate intodistinct layers on standing and from which fibers and films ofhomogeneous character can be spun, extruded or cast.

Example 10 2 g. of N,N-dimethylmethylitaconamate, 0.05 g. of potassiumpersulfate and 1 cc. of 7-ethyl-2-methylundecan- 4-sulfonic acid sodiumsalt (Tergitol No. 4) were added to 30 cc. of water. The resultingemulsion was then tumbled at 50 C. for 12 hours at the end of which time8 g. of acrylonitrile and 0.1 g. of potassium persulfate in 70 cc. ofwater were added. The reaction mixture was then tumbled for anadditional 12 hours at 50 C. The resulting polymer was obtained in an 88percent yield and contained 18 percent by weight of N,N-dirnethylmethylitaconamate by analysis. It was soluble in eitherN,N-dimethylformamide or N,N-dimethylacetamide.

Fibers obtained from a solution of a mechanical mixture of 70 partspolyacrylonitrile and 30 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.2 g. per denier,an extensibility of 20 percent, a sticking temperature of 220 C., andshrank 7 percent in boiling Water.

Example 11 3 g. of methylcitraconamate, 0.1 g. of ammonium persulfate,and 0.1 g. of sodium bisulfite and l g. of a sulfonated ether (Triton720) were added to 50 cc. of distilled water. The resulting emulsion wasthen heated for 12 hours at 45 C. with tumbling. A solution of 17 g. ofacrylonitrile, 0.2 g. of ammonium persulfate and 0.2 g. of sodiumbisulfite in 50 cc. of distilled water was then added. The reactionmixture was then heated for an additional 8 hours at 35 C. The resultingpolymer was obtained in an 89 percent yield and contained 15 percent byWeight of methylcitraconarnate by analysis.

Fibers obtained by extruding a solution of the polymer obtained in theabove example in a solvent such as N,N- dimethylformamide into aprecipitating bath had a tenacity of 3.9 g. per denier, an extensibilityof 21 percent, a sticking temperature of 220 C. and shrank 7 percent inboiling water.

Fibers obtained from a solution of a mechanical mixture of 60 partspolyacrylonitrile and 40 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 4 g. per denier,an extensibility of 20 percent, a sticking temperature of 225 C., andshrank 7 percent in boiling water.

Example 12 9.5 g. of N-methylisopropylcitraconamate were suspended incc. of water containing 0.1 g. of ammonium persulfate, 0.1 g. of sodiumbisulfite and 3 g. of a sulfonated ether type of emulsifying agent. Theresulting emulsion was then tumbled for 8 hours at 50 C., and aftercooling to room temperature, 2 g. of acrylonitrile, 0.05 g. of ammoniumpersulfate and 0.05 g. of sodium bisulfite were added. After tumblingthe reaction mixture for an additional 3 hours, at 40 C., a polymerproduct was obtained containing 5 percent acrylonitrile by analy- SIS.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give table solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Example 13 9 g. of N,N-dimethylbutylcitraconamate were suspended in 100cc. of water containing 0.1 g. of ammonium persulfate, 0.1 g. of sodiumbisulfite and 2.5 g. of a sulfomated ether type of emulsifying agent.The resulting emulsion was then tumbled for 8 hours at 50 C., and aftercooling to room temperature, 1 g. of acrylonitrile, 0.05 g. of ammoniumpersulfate and 0.05 g. of sodium bisulfite were added. After tumblingthe reaction mixture for an additional 6 hours at 35 C., :a polymer product was obtained which contained 9.8 percent acrylonitrilev Example 1420 g. of N-ethylmethylmaleamate were suspended in 150 cc. of water alongwith 0.2 g. of ammonium persulfate, 0.2 g. of sodium bisulfite and 4 cc.of 7-ethyl-2- methylundecan-4-sulfonic acid sodium salt (Tergitol N0.4). The resulting emulsion was heated for 16 hours at 50 C., and aftercooling to room temperature, there were added g. of acrylonitrile, 0.1g. of ammonium per-- sulfate and 0.1 g. of sodium .bisulfite. Thereaction mixture was heated for an additional 8 hours at 35 C. There wasthus obtained a polymer in a 92 percent yield which contained 29 percent.acrylon-it-rile by analysis.

Fibers obtained from a solution of a mechanical mixture of 80 partspolyacrylonitrile and 20 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.6 g. per denier,an extensibility of 21 percent, a sticking temperature of 220 C., andshrank 7 percent in boiling water.

As set forth in the preceding description and examples,

the resinous compositions or polymers of the invention which have from60 to 95 percent by weight of acrylonitrile in the polymer molecule areespecially useful for preparing fibers from their solutions or dopes inthe mentioned solvents by wet or dry spinning processes. Good qualityfibers can also be spun from dopes comprising a mixture of one or moreof the resinous compositions of the invention with polyacrylonitrile,when used in such proportions that the combined total of acrylonitrilein the mixture of components is in the range of 60 to 95 percent byweight, However, all .of the resinous compositions or polymers of theinvention, including mixtures of them with polyacrylonitrile in anyproportions but preferably in the proportions of from 5 to 95 percent byweight of one or more of the polymers of the invention and from 95 to 5percent by weight of polyacrylonitrile, can be made up into solutions ordopes with one or more of the mentioned solvents, with or Without addedfillers, pigments, dyes, plasticizers, etc., as desired, and the dopescoated onto a smooth surface to give flexible and tough films and sheetmaterials, which are useful fior photographic film support and otherpurposes.

Other solvents which can be used for the preparation of fibers andcoating compositions, etc., from the new resinous compositions orpolymers of the invention, and mixtures thereof with p olyacrylonitrile,include ethylene carbamate, ethylene carbonate, 'y-butyrolactone,N-rnethyl-Z-pyrrolidone, N,N-dimethyl methoxyacetamide, dimethylcyanamide, N,N-dimethyl cyanoacetamide, N,N-dimethyl-B-cyanopropionamide, glycolonitrile (formaldehyde cyanohydrin),malononitrile, ethylene cyanohydrin, d-imethylsulfioxide, dimethylsulfone, tetramethylene sulfone, tetramethylene sulfoxide, N-formylpyrrolidine, N- fiormyl morpholine, N,N-tetramethylene tetramethylenemethanephosphonamide, and the like. Generally speaking, we have foundthat N,N-dimethyl formamide and N,- N-dimethyl acetamide areparticularly advantageous solvents. The amount of polymer in the solventfor best spinning conditions can vary from about 5 to 20 percentalthough higher concentrations are possible at prohibitively hightemperatures for practical spinning operations.

What we claim is:

l. A process for preparing resinous compositions comprising heating inthe presence of a peroxide catalyst an aqueous dispersion of N-methylmethyl fumaramate, until the monomer has substantially completelyhomopolymerized, adding from 5 to percent by weight of acrylonitrilebased on the combined weights of the other monomer and acrylonitrile,and heating the reaction mixture until a substantial amount of theacrylonitrile has been polymerized.

2. A process for preparing resinous compositions comprising heating inthe presence of a polymerization catalyst an aqueous dispersion of analkyl fumaramate of not more than 16 carbon atoms wherein the said alkylgroup contains from 1 to 4 carbon atoms and containing no substituentother than N-alkyl groups of from 1 to 4 carbon atoms, until the saidalkyl fumaram'ate has substantially completely homopolymerized, addingfrom 5 to 95 percent by weight of acrylonitrile, based on the combinedweights of the said alkyl fumaramate and the acrylonitrile, and heatingthe reaction mixture until a substantial amount of the acrylonitrile hasbeen polymerized.

3. A modified resinous polymer containing from 5 to 95 percent by weightof acrylonitrile and having the structure and composition of a polymerobtained by the process of claim 1.

References Cited in the file of this patent UNITED STATES PATENTS2,620,324 Coover et a1. Dec. 2, 1952 2,649,434 Coover et a1 Aug. 18,1953 2,657,191 Coover et al Oct. 27, 1953

1. A PROCESS FOR PREPARING RESINOUS COMPOSITION COMPRISING HEATING INTHE PRESENCE OF A PEROXIDE CATALYST AN AQUEOUS DISPERSION OF N-METHYLMETHYL FUMARAMATE, UNTIL THE MONOMER HAS SUBSTANTIALLY COMPLETELYHOMOPOLYMERIZED, ADDING FROM 5 TO 95 PERCENT BY WEIGHT OF ACRYLONITRILEBASED ON THE COMBINED WEIGHTS OF THE OTHER MONOMER AND ACRYLONITRILE,AND HEATING THE REACTION MIXTURE UNTIL A SUBSTANTIAL AMOUNT OF THEACRYLONITRILE HAS BEEN POLYMERIZED.